apteriumn.
/apˈtɪərɪəm/ Ornithology.
Each of the featherless spaces on the skin of a bird intervening between the feathered tracts or pterylæ.
ΘΚΠ
the world > animals > birds > feather > [noun] > clump of or pteryla > space dividing or apterium
apterium1867
1867 W. S. Dallas tr. C. L. Nitzsch Pterylography 16 To these feathered bands I give the name of Feather-tracts or Contour-feather-tracts (pterylæ, Federn-fluren), and to the naked bands, or those which are not beset with contour-feathers, that of featherless spaces (apteria, Federn-raine).
1894 A. Newton et al. Dict. Birds: Pt. III 744 Feathers..are generally restricted to well-defined patches or tracts, which in 1833 received from Nitzsch..the name of pterylæ..or ‘feather-forests’, in opposition to the apteria, or featherless spaces, which intervene.
This entry has not yet been fully updated (first published 1933; most recently modified version published online March 2021).
<
n.1867